Simulated abdominal wall

ABSTRACT

A simulated abdominal wall for laparoscopic surgical training and methods of making the wall are provided. The simulated abdominal wall is dome-shaped having a visual appearance of an insufflated abdomen. Also, the wall is strong enough to withstand penetration with surgical trocars without unrealistic buckling or deformation. The wall is supported by a frame along the perimeter without any support structures traversing the wall that would interfere with port placement. The wall includes multiple layers connected together to form a unitary wall to fit a laparoscopic trainer. In one method, a projection of a dome is cut from a flat layer of foam material and assembled within a mold cavity. Consecutive layers with the same or different projection pattern are laid up inside the mold cavity. In another method, a vacuum mold together with heat is used to deform each foam layer. Adhesive is applied between layers to simultaneously join the adjacent layers upon deformation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. application Ser. No.16/018,361 filed on Jun. 26, 2018 entitled “Simulated abdominal wall”which is a continuation of International Patent Application No.PCT/US2017/039113 entitled “Simulated abdominal wall” filed on Jun. 23,2017 which claims priority to and benefit of U.S. Provisional PatentApplication Ser. No. 62/355,170 entitled “Simulated abdominal wall”filed on Jun. 27, 2016 all incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The present invention relates to the field of surgical training andsimulation and more specifically, to a simulated abdominal wall fortraining laparoscopic surgical skills.

BACKGROUND OF THE INVENTION

Minimally invasive surgical techniques such as laparoscopic surgery cangreatly improve patient outcomes because of reduced trauma to the body.There is, however, a steep learning curve associated with minimallyinvasive surgery. Accordingly, laparoscopic simulators, also known astrainers, have been developed to facilitate training surgeons on thesechallenging techniques. Trainers generally consist of an enclosure andsome type of barrier blocking direct observation of the interior of theenclosure where simulated organs or training platforms are located. Insome cases, the barrier is configured to be pierced by surgicalinstruments in order to gain access to the interior in order to observeand perform mock procedures and exercises.

The barrier serves to simulate an abdominal wall. In some cases,apertures may be pre-formed in the barrier to provide the simplest formof laparoscopic trainer. Laparoscopic instruments including scopes arepassed through the apertures, and a live feed of the interior of theenclosure is captured via a camera and viewed on an adjacent videomonitor. The surgeon observes the procedure on the video monitor duringthe operation. While much skill can be gained using simple trainers,efforts are being made to increase the fidelity of surgical simulation.More advanced laparoscopy simulators use different materials to mimicthe softness and pliability of the human abdominal wall. Previousversions have used layers of different types of flat foam sheets tosimulate the look and feel of the different types of tissue present inthe human abdominal wall. These sheets generally remain flat or arecurved only in one direction while simulating an abdominal wall.

A simulated abdominal wall must be strong enough to withstand the sameor similar forces encountered in real surgery including forces frompenetration of the simulated abdominal wall with a surgical trocar. Inorder to withstand such forces, the abdominal wall is generally asmaller sized insert in a larger and rigid representation of theabdomen. A small simulated abdominal wall and a larger one require sometype of support structure to prevent its collapse during use. Care mustbe given in selecting the type of support structure so as to not detractfrom the overall look and feel of the simulated abdominal wall, and tonot interfere with practice procedures especially during trocarplacement.

Generally, a simulated abdominal wall that is configured to bepenetrable by a surgical trocar is flat or curved only in one direction.While easy to manufacture, these designs present an aestheticshortcoming which greatly detracts from the realism of the simulation.Furthermore, in real laparoscopic procedures the interior of the abdomenis insufflated with gas and the patient's abdominal wall bows outwardlyto have a convex surface that curves in multiple directions. Whilesimulators do not use insufflation gas, it is desirable to represent thesame curvature and working space created by insufflation. A simulatedabdominal wall with a realistic curvature and also with anatomicallandmarks such as ribs or cartilage greatly aids the trainee in learningproper port placement. Proper port placement allows safe access to theabdominal cavity, and adequate triangulation for accessing the keyinternal anatomical structures throughout a surgical procedure. Thepresent invention presents a simulated abdominal wall suitable forlaparoscopic trainers that provides a more lifelike simulation and islarge enough to provide the user with a larger range of port placement.The present invention further presents methods to create a layered foamabdominal wall that is strong and does not require additional supportstructures to maintain its shape even during port placement. Thesimulated abdominal wall of the present invention also includesanatomical landmarks and has the visual appeal of a truly convex surfaceof an insufflated abdomen.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a simulated abdominal wallthat has a convex shape mimicking the visual appearance of aninsufflated human abdomen and requires no internal support structures tomaintain the shape is provided. The simulated abdominal wall includes amultiple of laminated layers of foam connected together with adhesive.The multiple layers increases the overall rigidity of the structurewhich springs back to its original shape after being deformed andretains enough rigidity to allow realistic puncture by trocars. An outerskin layer comprising a silicone layer mechanically bonded to foam layeris also part of the layered structure. Methods of manufacturing andintegrating the simulated abdominal wall with a laparoscopic trainer arealso provided.

According to another aspect of the invention, a simulated abdominal wallis provided. The simulated abdominal wall is configured to permit theuser to penetrate the simulated abdominal wall with a trocar anywherethrough its surface without interference from unrealistic underlyingand/or traversing support structures used for maintaining a bowed shape.The construction provides a realistic feel and is supported only aroundits perimeter without other support structures.

According to another aspect of the invention, a method for making asimulated abdominal wall is provided. The method includes providing aplanar first layer of the simulated abdominal wall. A firstthree-dimensional domed shape is projected onto a planar two-dimensionalsurface of the first layer to create a first projection. The firstprojection is cut out of the first layer to create a first cutout havinga first perimeter. A mold having a mold cavity is provided. The cavityhas a cavity surface that is sized and configured to receive the firstcutout. The first cutout is placed inside the mold cavity. Portions ofthe first perimeter are brought into juxtaposition to form the firstdomed shape in a loose fashion wherein the first domed shape has seamsdefined along the joined portions of the first perimeter. The firstdomed shape has an inner surface and an outer surface. A planar secondlayer of the simulated abdominal wall is provided. A second domed shapeis projected onto a planar surface of the second layer to create asecond projection. The second projection is cut from the second layer tocreate a second cutout having a second perimeter. The second cutout isplaced inside the mold cavity. Portions of the second perimeter arebrought into juxtaposition to form the second domed shape wherein thesecond domed shape has seams defined along the joined portions of thesecond perimeter. The second domed shape has an inner surface and anouter surface. The second domed shape is slightly smaller and placedinside the first domed shape such that the inner surface of the firstdomed shape faces the outer surface of the second domed shape.

According to another aspect of the invention, a method for making asimulated abdominal wall is provided. The method includes providing amold having hemispherical-like cavity. A plurality of planar cutouts ofdomed projections is also provided. Each cutout is assembled into a domehaving seams and nested consecutively inside each other inside thecavity. Adjacent cutouts are adhered to create a unitary simulatedabdominal wall made of a plurality of layers and having a dome-likeshape.

According to another aspect of the invention, a method for making asimulated abdominal wall is provided. The method includes providing avacuum mold having a mold cavity formed by a main body of the mold. Themain body of the mold defines a wall having an inner surface and anouter surface with a plurality of air holes extending across the wall inthe location of the mold cavity. At least one flat foam sheet isprovided and placed to cover the cavity. A pressure differential isapplied across the wall through the air holes of the main body. Heat isalso applied to the flat foam sheet. The flat foam sheet is deformedinto a deformed layer having a deformed shape as a result of applyingheat to soften the foam and the vacuum pulling the softened foam intothe mold. The deformed shape substantially corresponds to the shape ofthe mold cavity or previous layer or layers.

According to another aspect of the invention, a surgical training systemis provided. The surgical training system includes a base and a topcover connected to and spaced apart from the base to define an internalcavity. The top cover includes an opening and a frame connected to thetop cover in the location of the opening. A penetrable simulatedabdominal wall is connected to the frame and covers at least part of theopening. The simulated abdominal wall is dome-shaped having a convexsurface and a concave surface facing the cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional side view of surgical instruments inserted viatrocars to access simulated organs located inside a surgical simulatoraccording to the present invention.

FIG. 2 illustrates a simulated abdominal wall that is curved in onedirection.

FIG. 3 illustrates a simulated abdominal wall that is curved in twodirections according to the present invention.

FIG. 4A illustrates a surface of a dome projected onto a flat surfaceaccording to the present invention.

FIG. 4B illustrates the surface of FIG. 4A with its edges joinedtogether forming a dome according to the present invention.

FIG. 4C illustrates a surface of a dome projected onto a flat surfaceaccording to the present invention.

FIG. 4D illustrates the surface of FIG. 4C with its edges joinedtogether, forming a dome according to the present invention.

FIG. 5 is a transparent view of a mold used for the layup method forforming a simulated abdominal wall according to the present invention.

FIG. 6A illustrates the domed projection cutout of FIG. 4C above andprior to placement into the layup mold of FIG. 5 according to thepresent invention.

FIG. 6B illustrates the domed projection cutout of FIG. 4C with itsedges joined together inside the layup mold of FIG. 5 according to thepresent invention.

FIG. 6C illustrates the domed projection cutout of FIG. 4A above andprior to placement into the layup mold of FIG. 5 according to thepresent invention.

FIG. 6D illustrates the domed shape of FIG. 4B nested inside the domedshape of FIG. 4D inside the mold according to the present invention.

FIG. 7 is a sectional view of the layup mold of FIG. 5 with four foamlayers according to the present invention.

FIG. 8 is a top perspective, exploded view of a negative cavity vacuummold according to the present invention.

FIG. 9 is a top perspective, exploded, sectional view of a negativecavity vacuum mold according to the present invention.

FIG. 10 is a top perspective, sectional view of a negative cavity vacuummold according to the present invention.

FIG. 11 is a top perspective, sectional view of vacuum mold and a flatundeformed foam layer according to the present invention.

FIG. 12A is a top perspective, sectional view of a vacuum mold and aflat, undeformed foam layer according to the present invention.

FIG. 12B is a top perspective, sectional view of a vacuum mold and adeformed layer according to the present invention.

FIG. 13 is an exploded, sectional view of a vacuum mold, a deformedlayer and a flat undeformed layer according to the present invention.

FIG. 14A is a top perspective, sectional view of a vacuum mold, adeformed layer and a flat undeformed layer according to the presentinvention.

FIG. 14B is a top perspective, sectional view of a vacuum mold with twodeformed layers according to the present invention.

FIG. 15 is an exploded, sectional view of a vacuum mold, a plurality ofdeformed layers and one undeformed layer according to the presentinvention.

FIG. 16A is a top perspective view of an undeformed layer in place onthe vacuum mold and five previously deformed foam layers according tothe present invention.

FIG. 16B is a top perspective view of six deformed layers and a vacuummold according to the present invention.

FIG. 17A is a top perspective, exploded view of a vacuum mold, adeformed layer, an undeformed layer, and three bony inserts according tothe present invention.

FIG. 17B is a top perspective view of a vacuum mold, a deformed layer,an undeformed layer, and a bony insert adhered to the deformed layeraccording to the present invention.

FIG. 17C is a top perspective, sectional view of a vacuum mold, at leastone deformed layer, an undeformed layer, and a bony insert according tothe present invention.

FIG. 17D is a detailed sectional view of a vacuum mold, and a bonyinsert located between two deformed layers according to the presentinvention.

FIG. 18 is a top perspective view of a flat piece of foam, and anuncured sheet of silicone prior to being joined to make a skin layeraccording to the present invention.

FIG. 19A is a top perspective view of a skin foam layer in place on anuncured layer of silicone according to the present invention.

FIG. 19B is a top perspective view of a skin foam layer connected to acured layer of silicone trimmed of excess cured silicone according tothe present invention.

FIG. 20 is an exploded view of the vacuum mold, an undeformed skinlayer, previously deformed layers and a weighted plug used to join thepreviously deformed layers to the skin layer according to the presentinvention.

FIG. 21A is an exploded view of an undeformed skin layer in place on avacuum mold, previously deformed layers and a weighted plug according tothe present invention.

FIG. 21B is a top perspective view of a deformed skin layer, previouslydeformed layers and a weighted plug ready to be placed on top accordingto the present invention.

FIG. 21C is a top perspective view of a deformed skin layer shows theskin layer in place on the vacuum mold after forming, with previouslydeformed foam layers in place, and a weighted plug ready to be placedinside the cavity according to the present invention.

FIG. 21D is a top perspective view of a deformed skin layer inside avacuum mold, with the deformed foam layers and weighted plug in placeinside the cavity of a vacuum mold according to the present invention.

FIG. 22 is a top perspective view of a simulated abdominal wall for usein the assembly of the trainer according to the present invention.

FIG. 23 is a top perspective view of a final simulated abdominal wallfit into the simulated abdominal wall frame according to the presentinvention.

FIG. 24 is an exploded view of a simulated abdominal wall and two framehalves according to the present invention.

FIG. 25 is a partial cross-sectional view of an angled channel of thetwo frame halves and simulated abdominal wall compressed therebetweenaccording to the present invention.

FIG. 26A is a sectional view of a bottom frame half with retentionprotrusions according to the present invention.

FIG. 26B is a sectional view of simulated abdominal wall and frameaccording to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, a surgical simulator for laparoscopicprocedures, also known as a trainer, 10 is provided. The trainer 10allows a trainee to practice intricate surgical maneuvers in anenvironment that is safe and inexpensive. The trainer 10 generallyconsists of an enclosure 11 comprising an illuminated environment thatdefines an interior cavity 50. The interior cavity 50 is accessed withsurgical access devices such as trocars 12. The enclosure 11 is sizedand configured to replicate a surgical environment. For example, thetrainer 10 is configured as a portion of a human abdomen and, inparticular, configured to appear to be an insufflated abdominal cavity.Simulated organs 13 may be provided inside the enclosure 11. Thesimulated organs 13 are capable of being manipulated and “operated on”in mock procedures using real surgical instruments 14, such as but notlimited to graspers, dissectors, scissors and even energy-based fusionand cutting devices. Instead of simulated organs 13, the enclosure 11may be provided with an exercise platform configured for practicing oneor more techniques in isolation. For example, a suture board, instead ofsimulated organs 13, may be located inside the enclosure 11 for thepurpose of practicing suturing techniques.

The trainer 10 further includes a simulated abdominal wall 15. Thesimulated abdominal wall 15 generally covers the top of the trainer 10through which trocars 12 are placed. The simulated abdominal wall 15 isconnected to sidewalls of the trainer 10 or other frame structure thatconnects to the trainer 10. The simulated abdominal wall 15 is curved ina manner to improve the realism of the simulation. In one variation,this curvature mimics an insufflated abdominal wall. The simulatedabdominal wall 15 is further configured to provide a plurality of layersincluding but not limited to layers designed to represent skin, muscle,fat, bone, cartilage, and peritoneum. The simulated abdominal wall 15 isfurther configured to provide a realistic visual via a scope inside atrocar during penetration and, thereby, include all of the layers,characteristic colors, thickness and anatomical landmarks torealistically inform the surgeon of the progression through the layersand, thereby, teach prevention of accidental organ puncture. Thesimulated abdominal 15 wall must provide not only, a realistic visual,but also, a realistic tactile sensation that includes realistic forcelevels of the instruments through the simulated abdominal wall 15.

Turning to FIG. 2, an exemplary surface of a simulated abdominal wall 15curved in one direction is shown. The partial cylinder of the simulatedabdominal wall 15 is easy to manufacture and many of the prior trainers10 make use of such a simulated abdominal wall 15 that has a curvatureabout a single axis only. This shape is an approximation of the realshape of an insufflated abdomen. Additionally, the shape of FIG. 2 isnot as structurally sound as a shape that curves in two directions;therefore, abdominal wall designs that are curved in this way oftennecessitate the use of additional internal support structures. FIG. 3shows a simulated abdominal wall 15 surface that curves in twodirections. The partially spherical surface of FIG. 3 is both morelifelike, and also more structurally sound than a simulated abdominalwall surface that curves in only one direction. The simulated abdominalwall of the present invention eliminates the need for internal supportstructures while creating a shape that has a visual look and tactilefeel that more closely mimic the real abdominal wall.

A method for manufacturing a simulated abdominal wall is provided. Themethod includes the step of projecting a domed, three-dimensional shapeof the desired curvature onto a flat surface of a foam layer. Theprojection is cut out of the foam layer. Then the three-dimensionalsurface of a dome is formed from the projected two-dimensional surfaceof a cutout by bringing the edges of each cutout together forming seamsin a prescribed manner. Each cutout represents one or more anatomicallayers of a human abdominal wall. In the method, a plurality of cutouts,each sequentially slightly smaller are nested inside each other to buildup a complete domed abdominal wall structure. The layers are held inposition inside a mold having a conforming depression and laminatingtogether with the adhesive.

Turning to FIG. 4A, a cutout of a domed projection 16 is shown. Thecutout 16 is a transformation of the latitudes and longitudes oflocations from the surface of a dome into locations on a plane. The sameprojection 16 with its edges brought together in order to form adomelike shape 17 is shown in FIG. 4B. Similarly, FIG. 4C shows a cutoutof an alternate domed projection 18. The same projection 18 with itsedges brought together to form a hemisphere-like shape 19 is shown inFIG. 4D. One skilled in the art can contemplate different types ofcutout projections having different patterns than the ones shown inFIGS. 4A-4D. Also, the invention is not limited to hemisphericalprojections. Other domed shapes may also be projected. For example, anellipsoid or any curved surface may be projected in the presentinvention. The projections serve either as a layer or pattern forcutting sheets to form one or more domed layers that are to constitutethe simulated wall of the present invention as will be described ingreater detail below.

FIG. 5 shows a simple layup mold 20 that is used to form the layeredsimulated abdominal wall 15 according to the present invention. The mold20 includes a hemispherical depression sized and configured for thedesired shape of the final simulated abdominal wall 15. The depressionmay be semi-ellipsoidal, domed or curved in shape in another variation.The mold 20 is sized and configured to receive the cutout projectionswhen layering them up to form a multiplicity of layers glued togetherinto a multi-layered simulated abdominal wall 15. The layers are made offoam such as polyurethane foam, ethylene-vinyl acetate (EVA) foam,polyethylene foam, open cell foam, memory foam or silicone or acombination of silicone and foam. The polyurethane foam has a density ofapproximately 6 pound per cubic foot.

The size and shape of the depression of the mold conform closely to theshape of the assembled cutout projections. A cutout projection isassembled when its edges are joined together to form the desired shape.For example, in FIGS. 6A-6B, it can be seen that the cutout 18 fits intothe depression of layup mold 20, thus forming a hemisphere-like shape19. When the cutout 18 is located inside the mold 20, the edges of thecutout 18 are in juxtaposition to form seams 21 having a latitudinalorientation. FIG. 6C illustrates the cutout 16 in a flat orientationadjacent to the layup mold 20 containing the other cutout 18. Turningnow to FIG. 6D, cutout 16 is shown located inside the depression of mold20 with its edges together and nested inside the other cutout 18previously placed into the mold 20. Again, note the latitudinalorientation of seams 21 of cutout 18 forming dome 19 and compare to thelongitudinal orientation of seams 22 of cutout 16 forming dome 17. FIG.6D is a two-layered simulated abdominal wall 15. The number of layersmay be increased in a similar manner as described by alternating the twoor more curved surfaces 17 and 19 to build up the layers of thesimulated abdominal wall such that their seams do not align.

FIG. 7 illustrates a section view of mold 20 with alternating domes 17and 19 located in the mold 20. Each successive dome is sized to beslightly smaller to account for the thickness of each prior foam layer.Also, in one variation, each added dome alternates between at least twoor more different cutout projections, lest the seams line up through thefoam layers, which would result in a foam piece with reduced or nostructural integrity. Alternatively, the same cutout projection may beemployed for each layer such that each subsequent layer isrotated/displaced slightly to avoid alignment of the seams with theseams of the previous layer. For example, the cutout projection 16 ofFIG. 4A can be rotated inside the mold 20 relative to the previouslyplaced cutout projection 16 such that the seams 22 are offset and notaligned. It should be noted that different types and colors of foamsheets may be used to simulate the look of the layers present in a humanabdominal wall. Adhesive is applied between the cutout projections toadhere the layers to form the abdominal wall.

By cutting flat sheets in a pattern and forming a three-dimensional domefrom the combined flat sheets as described above, a resilient convexsurface is created. Furthermore, because adhesive is applied only on thelarge flat surfaces of the foam and not directly to the thickness of theseams, there are no areas in the simulated abdominal wall where thestiffness is greater than the surrounding areas due to a thick seam ofglue. Once all of the desired underlying layers have been laminatedtogether, a foam/silicone skin layer is stretched and adhered to thework-piece. The skin layer covers up all of the seams, leaving a smoothconvex surface visible to the user. The foam/silicone skin layer will bedescribed in greater detail below.

In another method, a vacuum mold is used to form flat foam sheets intoconvex foam sheets and join them together. In this method, a flat foamsheet is placed on the vacuum mold and held in place with a frame. Thevacuum pump is then turned on, and heat is applied to the foam. The heatrelaxes the foam, allowing it to yield and stretch into the mold cavitydue to the suction of the vacuum. Spray adhesive is applied to the foamin the mold and to a new sheet of foam. Next, a multitude of holes arepoked through the first layer of foam so that the vacuum can act on thesecond layer of foam through the first. The order of hole-poking andglue application can be reversed and the process will still work. Theframe is removed, the next sheet of foam is placed glue side down ontothe vacuum mold with the first foam layer still in place, glue side up,and the frame is replaced. Again, the vacuum pump is turned on and heatis applied to the top foam layer. As the two foam layers come intocontact they are bonded together. This process is then repeated for eachdesired foam layer. With the addition of each foam layer, the simulatedabdominal wall gains strength. Once the desired foam layer configurationis met, the simulated abdominal wall is then inserted into an abdominalwall frame, which is a two piece component that secures the simulatedabdominal wall along the perimeter only by compressing it between topand bottom frame parts and allows the user to easily install and takeoff the wall/frame assembly from the surgical simulator enclosure. Thegeometry of the abdominal wall frame adds further support to the convexform and feel of the simulated abdominal wall by utilizing an angledchannel along the perimeter that the simulated abdominal wall iscompressed between. The method will be described in greater detail withreference to the drawings hereinbelow.

Turning now to FIG. 8, an exploded view of a negative cavity vacuum mold51 is shown. The vacuum mold 51 includes a base 23, air outlet 24, frame25, and main body 26 having a negative cavity 28. FIG. 9 shows anexploded sectional view of the same vacuum mold 51. In this view, airholes 27 are seen to pierce the cavity 28. FIG. 10 shows a collapsed,sectional view of the vacuum mold 51 showing the plenum 29 createdbetween the base 23 and main body 26, the plenum 29 is sealed betweenthe base 23 and main body 26, as well as between the main body 26 andframe 25 and in fluid communication with the air outlet 24.

With reference now to FIG. 11, a first flat sheet 32 a of foam materialis located above the main body 26 of the vacuum mold 51 and underneaththe frame 25 which keeps the flat sheet 32 a in place with respect tothe mold 51. FIG. 12A shows the flat foam sheet 32 prior to forming.During the forming process, air is evacuated through air outlet 24,which creates negative pressure in the plenum 29. This negative pressureacts through air holes 27, and sucks the flat foam sheet 32 towards theinner surface of the cavity 28. While air is being evacuated throughoutlet 24, heat is applied, such as with a hot air gun or integratedheating element, to the top of the foam sheet 32. The heat allows thefoam sheet 32 to stretch and conform to the shape of the cavity 28making complete contact with the surface of the cavity 28. The heat isgenerally applied simultaneously with the application of vacuum to thesheet; although the invention is not so limited and heat may be appliedprior to vacuum. A deformed foam sheet 33 a molded in the vacuum mold 51is shown in FIG. 12B.

With reference now to FIGS. 13 and 14A, the frame 25 is lifted and asecond flat undeformed sheet 32 b is placed atop the main body 26 andunderneath the frame 25 of the vacuum mold 51. Prior to placement of thesecond undeformed sheet 32 b into the vacuum mold 51, a multitude ofholes are poked through the previously formed first layer 33 a to allowthe suction to act through its thickness, thus pulling the secondundeformed, flat sheet 32 b into the cavity 28. The holes are poked witha cylindrical roller having a plurality of spikes. The spikes are longenough to penetrate the thickest layer and are approximately 0.75 incheslong. The radius of the cylinder of the roller is approximately 1.25inches. Thereby, the roller is large enough with spikes spread apartfrom each other to avoid tearing the foam. Also, the roller is smallenough so that it can still perforate the areas of the foam in thecavity with a minimum radius of curvature of approximately 1.7 incheswhich is approximately the same radius of curvature of the abdominalwall in one variation. The holes are approximately 2 millimeters indiameter. The second flat sheet 32 b is also made of foam. Prior toplacement in the vacuum mold 51, adhesive is applied to the top side ofthe first formed foam layer 33 a to adhere the two adjacent layers toeach other. Adhesive may also be applied to the underside surface of thesecond undeformed flat sheet 32 b that faces the first foam layer 33 ato adhere the layers to each other. Contact cement includingsolvent-based or water-based contact adhesive, which stays soft andflexible, may be employed so that the adhesive does not interfere withthe look and feel of the final product. Also, the adhesive is selectedand carefully applied so as to not create too much drag when a trocar ispushed through the skin layer. FIG. 14B shows the second flat sheetsimultaneously formed and adhered to the first formed foam sheet 33 a.The intermediate result is a simulated abdominal wall 15 having twoformed layers 33 a, 33 b glued together. The process can be repeated tobuild up a simulated abdominal wall having as many layers as desired.Again, different types and colors of foam, such as any flexiblethermoplastic foam, may be used for each layer to simulate the colorsand textures present in a real abdominal wall. For example, red andwhite layers can be made of ethylene-vinyl acetate having a density ofapproximately 2-4 pounds per cubic foot, pink and translucent layers canbe made of closed-cell polyethylene.

FIG. 15 illustrates the process described above after severalrepetitions wherein a flat foam sheet 32 is placed atop a plurality ofpreviously deformed layers 33 and pressed against the pre-made foamlayers 33 using the frame 25. FIGS. 16A and 16B show an undeformed layerprior to and after vacuum molding. Again, between adding layers, amultitude of small holes through the deformed foam layers 33 is providedto place the undeformed layer in fluid communication with the vacuumacross the main body 26 and across the previously deformed layers 33.Adhesive is applied to the top of the previously deformed layers 33 andto the underside of the flat undeformed foam layer 32. When the vacuumis activated and the heat applied the undeformed layer will besimultaneously deformed and adhered to the previously deformed layer.

In one variation of this process, at least one insert 35 is providedbetween two layers as can be seen in FIGS. 17A-17D. At least one foamlayer 33 has already been deformed by the vacuum mold and is locatedinside the cavity 28. Prior to placing a flat foam sheet 32 and frame 25onto at least one previously deformed foam layer 33, at least one bonyinsert 35 is glued in place on the upper surface of the last deformedfoam layer 33 b. FIG. 17B shows the bony insert 35 glued in place on topof the pre-made foam layers 33. Adhesive is also applied to the top sideof the bony insert 35, and a subsequent flat foam sheet 32 is placed ontop and held in place with frame 25 as shown in FIG. 17C. FIG. 17D showsthe bony insert 35 sandwiched and enclosed between two deformed layers33 b and 33 c creating a simulated abdominal wall with a bony insert.Other adjacent layers 33 may include bone inserts 35 therebetween.Although the word “bony” is used, the invention is not so limited andbony inserts not only represent bone in the anatomy, but may representany other anatomical structure of increased rigidity relative to thefoam layers such as cartilage, muscle, bones, tumors and the like or ofdecreased rigidity relative to the layers such as blood vessels, nervesand the like. To replicate bone, the bony inserts 35 are made of rigidplastic. To replicate nerves or vessels, the bony inserts 35 may be madeof soft silicone. The inserts may be made from but not limited to thefollowing materials: polypropylene, styrene, polyethylene, nylon, paper,cardstock, polyvinyl chloride, polyethylene terephthalate, polyethylene,terephthalate glycol-modified, and acetal homopolymer resin.

Turning now to FIG. 18, forming an outer skin layer 39 will now bedescribed. The skin layer includes a skin foam layer 37 and a siliconelayer 38. In one variation, the skin foam layer 37 is made of memoryfoam. In making the skin layer, the foam layer 37 is placed on anuncured silicone layer 38 as shown in FIG. 19A and the silicone layer 38is allowed to cure. When the silicone cures on the foam, it creates amechanical bond with the slightly porous foam material. As the siliconecures, it interlocks with the pores of the foam material. Once thesilicone is fully cured, the excess is trimmed resulting in the trimmedskin layer 39. Because the silicone is securely bonded to the underlyingfoam, a much more durable skin layer is realized, and costs are drivendown by reducing the frequency of abdominal wall replacement. Thecombination of foam and silicone closely adhered together via the curingprocess makes both layers easily deformed in the vacuum mold and furthereasily adhered to the rest of the deformed layers. Furthermore, inprevious versions where the outer skin layer is not bound to theunderlying layers, unrealistic spaces open up between the simulatedabdominal wall layers during port placement visible to the surgeon. Thepresent invention eliminates this issue because the silicone ismechanically bonded to a foam layer which is easily deformed and adheredto other foam layers.

Turning now to FIGS. 20-21, after the skin layer 39 is prepared, it isplaced inside the cavity 28 of the vacuum mold 20 followed by the frame25. The trimmed skin layer 39 is positioned with the silicone skin layer38 facing the main body 26 of the mold 20. FIG. 21A shows the trimmedskin layer 39 held in place on the vacuum mold's main body 26 by theframe 25 prior to evacuation of the vacuum mold. FIG. 21 B shows thetrimmed skin layer 39 pulled into the cavity 28 of the vacuum mold as aresult of activation of a vacuum inside the plenum 29. In FIG. 21B, thepreviously deformed foam layers 33 with or without bony inserts 35 areready to be pressed down into the cavity by the weighted plug 40. FIG.21C shows the previously deformed foam layers 33 glued into a unitarybody placed into the cavity 28 on top of the trimmed and deformed skinlayer 39. Adhesive is added between the skin layer 39 and uppermost foamlayer 33 to adhere the skin layer 39 to the rest of the deformed layers33. FIG. 21D shows the placement of the weighted plug 40 on top of thepreviously deformed foam layers 33. The weighted plug 40 helps to pressall of the layers together to uniformly adhere the different layersuntil the glue dries. FIG. 22 shows the final simulated abdominal wall15 in its finished state prior to having its edges bound into a trainer10 by a frame having top and bottom halves 43, 44 as will be describedhereinbelow. The final simulated abdominal wall 15 has a polygonalfootprint. The simulated skin layer 39 may also be employed in a similarmanner with the variation of FIGS. 4-7 wherein the completeddomed-shaped skin layer 39 is adhered to the one or more domed cutoutlayer wherein the domed cutout layer(s) may themselves be bondedtogether.

With reference to FIGS. 23-26, the simulated abdominal wall 15 isinserted into a simulated abdominal wall frame 45 which is a two-piecesystem including a top half 43 and a bottom half 44 that secures thesimulated abdominal wall from the perimeter only by compressing the foamlayers. The framed abdominal wall 15 is then removably fixed into alaparoscopic trainer 10. FIG. 24 shows the exploded view of thesimulated abdominal wall 15 and frame assembly 43, 44 comprised of thesimulated abdominal wall 15, top frame 43, and bottom frame 44. The topframe 43 and bottom frame 44 can be assembled together via screws orother fastener such as a snap-fit engagement in the case of a re-usableframe system, or snapped together via heat staking or other low costassembly method.

With reference to FIG. 25, the simulated abdominal wall frame 45includes an angled channel 46 in which the simulated abdominal wall 15is compressed to secure it into the frame 45. The angled channel 46 iscreated by the top and bottom frame components 43, 44. If the simulatedabdominal wall 15 was compressed between two flat frames, it wouldweaken the structure and it would invert/collapse during use much moreeasily. The channel 46 is angled from the vertical axis toward themiddle of the simulated abdominal wall 15. This angle follows thecontour of the convex form of the simulated abdominal wall 15 andsignificantly strengthens and increases the support provided to theconvex form of the simulated abdominal wall 15. Without this feature thesimulated abdominal wall would invert during use much more easily.

As shown in FIGS. 26A-26B, the bottom frame 44 includes upwardprotrusions 47 that are spaced around the perimeter of the bottom frame44. These retaining protrusions 47 can also be present on the top frame43, or both frame halves 43, 44. These teeth-like retaining protrusions47 provide additional retention of the simulated abdominal wall 15within the simulated abdominal wall frame 45 by pressing or biting intothe simulated abdominal wall as it is compressed between the frame top43 and frame bottom 44. With reference to FIG. 26B, a simulatedabdominal wall 15 is compressed between the two frame halves 43, 44 andis pierced by a retaining protrusion 47. Alternatively, rubberized padsor double-sided tape may be employed together with or without theprotrusions to retain the abdominal wall 15.

The design of the frame 45 allows the user to easily install and removethe wall/frame assembly from the surgical simulator enclosure. Thegeometry of the abdominal wall frame adds further support to the convexform of the simulated abdominal wall by utilizing an angled channelalong the perimeter that the simulated abdominal wall is compressedbetween, which follows the natural shape of the simulated abdominalwall. Simply compressing the simulated abdominal wall between flat framehalves would result in significantly reduced support for the convex formand feel of the simulated abdominal wall, which would likely result inunwanted inversion during normal use.

The methods described above rely on a bent lamination mechanism formedin part by successively gluing surfaces together that have been made tocurve. A structure that maintains the desired curvature emerges witheach additional layer. The first method combines this gluing of curvedlayers with cutouts that have been made in the shape of a curved surfaceprojected onto a flat surface. Different cutout patterns are alternatedso that the seams of the cutouts do not align to weaken the structure,or alternatively, a cutout may be displaced/rotated with respect to theprevious later having the same pattern to offset the seams from eachother.

The second method uses vacuum forming to achieve curved surfaces andavoids seams across the surface altogether. Flat sheets of foam areplaced over a negative cavity vacuum mold, a frame is placed over thefoam to make an air-tight seal, and the vacuum mold is evacuated. As thevacuum is pulled, heat is applied to the foam, which allows the foam toyield and stretch into the mold cavity. When a new layer is to be added,a multitude of holes are poked through the previously-formed foamlayers. Adhesive is applied between the layers so that they form a bondacross the entire curved surface. After several layers of foam have beenlaminated together, the work-piece begins to maintain the curved shapeof the mold. By adding or removing layers, the tactile response of thefoam layers can be tailored for more lifelike feel.

Additionally, rigid or semi-rigid pieces may be added between the foamlayers to simulate bony or other anatomy in any of the methods describedherein. It should be noted that these bony inserts are not required forstructural support. Instead, the bony inserts give the user landmarksfor proper port placement, and also prevent port placement in the wrongarea. Palpation is a common technique used for proper port placement,which is a crucial part of a successful procedure, and the bony insertspermit the user to train on palpation and proper port placementsuccessfully. The bony inserts advantageously improve the realistic feelof the model.

It should be noted that while two methods are described here forlayering pre-made foam sheets in order to create a curved surface withstructural integrity, it would also be possible to create a casting moldthat allows the user to sequentially build up a multitude of curvedlayers that are adhered to one another across their entire surface.

It is understood that various modifications may be made to theembodiments disclosed herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplifications ofpreferred embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the present disclosure.

We claim:
 1. A method for making a simulated abdominal wall, the methodcomprising the steps of: providing a mold having a domed cavity;providing a plurality of planar cutouts of domed projections; assemblingeach cutout into a dome having seams; nesting each cutout consecutivelyinside each other inside the cavity; and adhering adjacent cutouts. 2.The method of claim 1 wherein the plurality of planar cutouts are of twoor more different domed projections.
 3. The method of claim 1 wherein atleast two adjacent cutouts from the plurality of planar cutouts have thesame domed projections; and the step of assembling each cutout includesoffsetting the seams of adjacent cutouts.
 4. The method of claim 1further comprising the step of offsetting the seams of adjacent cutouts.5. The method of claim 1 further comprising the step of providing aninsert between two adjacent cutouts of the plurality of planar cutouts.6. The method of claim 1 further comprising the step of removing thecutouts from the mold cavity after the step of adhering adjacentcutouts.
 7. The method of claim 1 further comprising the step of forminga unitary dome having a plurality of layers comprising cutouts; theunitary dome having a convex surface and a concave surface.
 8. Asimulated abdominal wall produced by the method of claim
 1. 9. A methodfor making a simulated abdominal wall, the method comprising the stepsof: providing a vacuum mold having a mold cavity formed by a main bodyof the mold; the main body defining a wall having an inner surface andan outer surface with a plurality of air holes extending across the wallin the location of the mold cavity; providing a flat foam sheet; placingthe flat foam sheet so as to cover the cavity; applying a vacuum acrossthe wall through the air holes of the main body; applying heat to theflat foam sheet; and deforming the flat foam sheet into a deformed layerhaving a deformed shape as a result of applying a vacuum and applyingheat; the deformed shape substantially corresponding to the shape of themold cavity.
 10. The method of claim 9 further comprising the step ofrepeating the steps of providing a flat foam sheet, placing, applying avacuum, applying heat and deforming to form an abdominal wall having aplurality of layers.
 11. The method of claim 10 further comprising thestep of applying adhesive between at least two of the layers.
 12. Themethod of claim 10 further comprising the step of bonding adjacentlayers together.
 13. The method of claim 12 wherein the step of bondingadjacent layers comprises bonding adjacent layers simultaneously withthe step of deforming.
 14. The method of claim 9 further comprising thestep of forming holes across the deformed layer in the location of themold cavity to place a consecutive flat foam sheet in fluidcommunication with the plurality of air holes.
 15. The method of claim14 further comprising the step of placing the consecutive flat foamsheet in fluid communication with the vacuum.
 16. The method of claim 9wherein the steps of applying a vacuum and applying heat are performedsimultaneously.
 17. The method of claim 10 further comprising the stepof placing a bony insert between two adjacent layers.
 18. The method ofclaim 17 further comprising the step of adhering the bony insert to atleast one of the two adjacent layer.
 19. The method of claim 17 furthercomprising the step of applying adhesive to the bony insert.
 20. Asimulated abdominal wall produced by the method of claim 9.